This invention relates to smoking articles, and more particularly to smoking articles including liquid flavor strands, and the apparatus and process for making such articles.
The addition of flavorants and other additives to tobacco filler during cigarette manufacturing is a common practice. It is important that the additives are applied in consistent concentrations throughout the smoking article, such that each article has the same burn and flavor characteristics from puff to puff. However, the known techniques suffer from various technical problems.
Additives may be applied to tobacco filler by treating the filler prior to sending the tobacco to the cigarette-making machine. However, it is difficult to achieve a uniform application of additives by spraying bulk tobacco. Also, because many additives are volatile compounds, some of the flavoring may escape from the tobacco during processing.
Certain additives, due to their viscous properties, must be sprayed onto the tobacco filler in very dilute forms. However, the solvent (typically aqueous) used to dilute the additives tends to disperse and saturate the tobacco, requiring an additional drying load. Also, some desirable additives applied to the tobacco are sticky and may gum up or contaminate the cigarette maker during the cigarette making process. Liquid additives applied to the tobacco to provide a uniform surface coating on the tobacco particles can potentially stain the paper cigarette wrapper of the finished cigarette.
Additives may be applied to tobacco filler using a foaming process. By using air to dilute the additive (instead of water or other liquid solvents) the foaming process allows even application of the additives to the tobacco filler without staining the paper cigarette wrapper, but the liquid to be foamed must have a relatively low viscosity. Hence, any flavorants added using the foaming process must form a relatively non-viscous solution.
In view of the foregoing, it is an object of this invention to provide a method for incorporating selected materials into a cigarette rod so that the materials are applied in consistent concentrations throughout the length of the article.
It is another object of this invention to provide for incorporating selected materials into cigarettes at the rod forming stage in the manufacturing process.
It is another object of this invention to provide a method for selectively varying, along the length of the rod, the concentrations of the materials added to a cigarette.
It is yet another object of this invention to provide for incorporating selected materials into cigarette rods during the manufacturing process without using excessive amounts of solvents.